Irradiation is an early determinant of endothelial injury during hematopoietic stem cell transplantation.
OBJECTIVE
We investigated the degree and the time course of endothelial injury in mice pretreated with lethal or reduced-intensity irradiation administered before transplantation.


METHODS
Six- to eight-week-old female mice were randomly allocated into three groups: lethal-intensity irradiation (8.5 Gy, group 1), reduced-intensity irradiation (5.0 Gy, group 2), or nonirradiated controls (group 3). After conditioning, circulating endothelial cells (CD31+, CD133(-), and CD45low) and peripheral blood CD4+ or CD8+ T-lymphocyte subpopulations were enumerated using flow cytometry at various times. The morphologic changes in endothelium were examined at phase-contrast light microscopy.


RESULTS
Circulating endothelial cells showed an earlier and higher peak in the lethal irradiation group compared with the reduced-intensity irradiation group, which exhibited a protean elevation in cell numbers. There were no visible histopathologic changes during the early stage of endothelial damage.


CONCLUSIONS
Lethal and reduced doses of irradiation induced endothelial injury in a dose-dependent manner. Endothelial damage may occur before graft-vs-host disease and its related complications.
Zeng
L
L
Department of Immunology, Xuzhou Medical College, Xuzhou, China.
Yan
Z
Z
Wang
L
L
Du
B
B
Pan
X
X
Xu
K
K
D000818:Animals; D001808:Blood Vessels / Q000276:immunology / Q000528:radiation effects; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000528:radiation effects; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D042783:Endothelial Cells / Q000473:pathology / Q000528:radiation effects*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D007422:Intestines / Q000276:immunology / Q000528:radiation effects; D008099:Liver / Q000276:immunology / Q000473:pathology / Q000528:radiation effects; D051379:Mice; D008807:Mice, Inbred BALB C; D010974:Platelet Aggregation / Q000528:radiation effects; D011832:Radiation Injuries / Q000473:pathology*; D012867:Skin / Q000276:immunology / Q000528:radiation effects; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects